Recent increases in demand for oil, associated price increases, and environmental issues are continuing to exert pressure on an already stretched world energy infrastructure. Natural gas, with an estimated 60-70 year reserve, represents a clean and abundant fossil fuel that could transition from this troubled oil and gasoline dominated market to the expected eventual adoption of renewable energy and hydrogen. However, one of the hurdles to widespread use of natural gas in automobiles and power plants is storage of the gas. An ideal gas storage vessel should contain gas at reasonable temperatures and pressures while maintaining a low weight, a small volume, and minimal cost. There are problems associated with highly compressed natural gas (CNG) and cryogenic liquid natural gas (LNG). One of the favored alternatives to these two storage methods is natural gas adsorbed on a microporous medium such as activated carbon. Adsorbed natural gas (ANG) has demonstrated storage performance competitive with CNG, but at pressures as low as 3.45 MPa (compared to 15.17 MPa for CNG). This relatively low pressure allows for easier tank filling, provides room for non-cylinder form factors, allows for optional tank materials and increases the safety of a tank.
Activated carbon is the dominant material in research on storage of adsorbed methane and is typically synthesized by pyrolysis (i.e., carbonization) and activation treatments on existing organic materials such as coconut fibers, carbon fibers, and even tire rubber. However, few of these precursor materials can be easily engineered to any significant degree.
A need exists for a carbon cryogel having a microporous structure that can be tuned by varying sol-gel parameters to produce a carbon cryogel for low pressure methane storage. The present invention seeks to fulfill this need and provides further related advantages.